I'm trying to do my first tests of reading large xlsx file with POI, but to do a simple test with a small file I fail to show the value of a cell.
Someone can tell me what is my mistake. All the suggestions are welcome. Thanks.
Test.java:
import java.io.File;
import java.io.FileInputStream;
import org.apache.poi.openxml4j.opc.OPCPackage;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.xssf.streaming.SXSSFWorkbook;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
public class Test {
public static void main(String[] args) throws Throwable {
File file = new File("/tmp/test.xlsx");
OPCPackage pkg = OPCPackage.open(new FileInputStream(file.getAbsolutePath()));
XSSFWorkbook xssfwb = new XSSFWorkbook(pkg);
SXSSFWorkbook wb = new SXSSFWorkbook(xssfwb, 100);
Sheet sh = wb.getSheet("Hola");
System.out.println("Name: "+sh.getSheetName()); // Line 19
System.out.println("Val: "+sh.getRow(1).getCell(1).getStringCellValue()); // Line 20
}
}
Result:
Name: Hola
Exception in thread "main" java.lang.NullPointerException
at Test.main(Test.java:20)
test.xlsx:
Please consult: similar question SXSSFWorkBook is write only, it doesn't support reading.
For low memory reading of .xlsx files, you should look at the XSSF and SAX EventModel documentation : Gagravarr
If memory wouldn't be an issue you could use a XSSFSheet instead e.g.
File file = new File("D:/temp/test.xlsx");
FileInputStream fis = new FileInputStream(file);
XSSFWorkbook wb = new XSSFWorkbook(fis);
XSSFSheet sh = wb.getSheet("Hola");
System.out.println(sh.getLastRowNum());
System.out.println("Name: "+sh.getSheetName());
Row row = sh.getRow(1);
System.out.println(row.getRowNum());
System.out.println("Val: "+sh.getRow(1).getCell(1).getStringCellValue());